Sweeteners: Harmless, Poisonous, or Fattening?

We’ve heard about the dangers of sugar, whether it comes as granulated cane sugar, the dreaded high fructose corn syrup, or “natural” honey. All of these high calorie sweeteners will cause spikes in blood sugar and insulin secretion, with the associated energy high and subsequent crash. Over consumption can lead to the obesity-related illnesses of which we are all becoming aware: heart disease, Type II diabetes, stroke, and more (See metabolic syndrome).

But, we like sweet stuff! So, how can we, as the saying goes, have our cake and eat it? Many have turned to artificial sweeteners like sucralose (Splenda), saccharin (SweetnLow), aspartame (Equal) or its derivative neotame (Nutrasweet), and the latest, Truvia. These chemicals can now be found in diet drinks, baby foods, diet ice creams, diet candy, and even Lean Pockets. They are said to be safe (and Truvia is even touted as natural), but do they help you lose weight?

According to a paper in the Yale Journal of Biology and Medicine, no. In fact, they report that epidemiological data show a “positive correlation between artificial sweetener use and weight gain.” Controlled studies indicate that this increase in weight is not because the artificial sweeteners are in themselves fattening, but because those using artificial sweeteners eat more.

Some have speculated that this is because dieters over-compensate for the calories they think they “save” by using artificial sweeteners. How many of us have ordered a Big Mac meal with a diet Coke?

But Dr. Yang is suggesting that there is a more insidious mechanism at work. It is known that, in humans, sweet taste enhances appetite. However, because we are “wired” for a balance between energy consumption and expenditure, the postingestive effects of eating real sugar reduce subsequent enjoyment of sugar–we lose our appetite. Artificial sweeteners do not trigger these natural energy balance mechanisms simply because they do not make us “full.” In fact, it has been hypothesized that consumption of these noncaloric and extremely sweet substances desensitizes us to our natural “stop” signals, so we eat even when not hungry and crave increasing amounts of sweet flavor. So, we eat more.

Take home message? Artificial sweeteners may be safe, or so we are told, but they do not help reduce weight. So why use them?